Apparatus and Method for Fastening a Composite Pole to the Ground

ABSTRACT

A fastening element is for fastening a hollow composite pole to the ground at a location where a slit-formed opening is present in the ground. The fastening element has a lower end portion that is configured for being positioned in the slit-formed opening, wherein a conical portion of the composite pole is abutting a conical upper portion of the fastening element. A method is for fastening a hollow composite pole to the ground.

FIELD OF THE INVENTION

This invention relates to an apparatus for fastening a hollow composite pole to the ground where a slit formed opening is present in the ground. The invention also relates to a method for fastening a hollow composite pole to the ground.

BACKGROUND OF THE INVENTION

It is known to fasten composite poles in the ground by excavating a recess, and thereafter positioning the composite pule in the recess and till in around the pole. Regarding poles for overhead power lines, such a method will often involve relatively large environmental damage, particularly when a recess is made in rock. When fastening poles by use of said method, frost damage may occur due insufficient draining.

It is also known to mount a composite pole to a column raised from the ground. The column may be made from concrete and having reinforcement that extends into the ground. The composite pole may be inserted over the column. If the column is made from concrete, it is necessary to bring the concrete to the position of the column often by use of a helicopter, or make concrete at the position of the column. Both methods comprises extra costs and work.

WO2004/101914 discloses a hollow pole that is drilled into a slit the ground.

Documents EP1911912A2, WO2004/101914A1, GB2444411 and GB2429229A show other solutions from the prior art.

SUMMARY OF THE INVENTION

The invention has for its object to remedy or to reduce at least one of the drawbacks of the prior art, or at least provide a useful alternative to prior art.

The object is achieved through features, which are specified in the description below and in the claims that follow.

The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention.

In a first aspect, the invention relates more particularly to fastening element in accordance with claim 1.

The invention concerns having a slit-formed opening, preferably circular, in the ground, where a fastening element is positioned in the slit-formed opening. The fastening element has a conical upper portion above the ground. A hollow composite pole, has a complementary conical inner portion at its lower end, and is positioned on and abutting the fastening element.

By hollow means that the composite pole must have an inner opening, at least in the portion that is moved over the fastening element.

The slit formed opening may be circular and formed by drilling or hammering a body into the ground.

The fastening element may be equipped with drill elements at its lower end portion to enable the fastening element to be used as a drill.

The drill elements may comprise metal or ceramic material or combinations thereof.

In a second aspect the invention relates more particularly to a method for fastening a hollow composite pole for overhead power lines to the ground in accordance with claim 6.

The method comprises fixing the fastening element to the ground, for instance by adhesive or a concrete based material.

The method may comprise making the slit formed opening by drilling into the ground.

The method may comprise making the slit formed opening by hammering the fastening element into the ground.

The method comprises providing the lower end portion of the fastening element with drill elements and drilling the fastening element into the ground.

The fastening element may be made from composite material or metal or combinations thereof.

If parts of the ground that is positioned on the inner side of the slit should loosen or where it is advantageous to have it removed partly or fully, the material on the inner side of the slit may be at least partly removed.

When drilling in soil or march, it may be advantageous to have frost in the ground to avoid movement in the ground during drilling.

Tests show that the drill or the fastening element must be aligned with the vertical axes prior to being moved into the ground.

The apparatus and method according to invention solves the problem of fastening a hollow composite pole to the ground in a relatively simple and cost effective way.

BRIEF INTRODUCTION OF THE DRAWINGS

In the following is described examples of preferred embodiments and methods illustrated in the accompanying drawings, wherein:

FIG. 1 shows a vertical section of a drill and a power drill during drilling of a slit formed opening in the ground according to the invention;

FIG. 2 shows a vertical section of a composite pole that has been moved into the slit formed opening that was drilled by use of the drill in FIG. 1;

FIG. 3 shows an embodiment where a fastening element has been moved into the slit formed opening that is drilled by the use of the drill shown in FIG. 1, and where the fastening element is fixed to the composite mast;

FIG. 4 shows another embodiment where the fastening element, at its lower portion, is equipped with drill bodies:

FIG. 5 shows a section IV-IV in FIG. 4; and

FIG. 6 shows in a larger scale a segment V-V in FIG. 5 of the lower portion pf the fastening element and a drill body.

DETAILED DESCRIPTION OF THE EMBODIMENTS

On the drawings, the reference numeral 1 denotes a drill that by the help of a power drill 2 is under displacement into the ground 4. The ground 4 may constitute for example rock, soil, or march, alternatively combination thereof.

The power drill 2 is typically aligned and is fixed to the ground 4 or another suitable, not shown device. There after the power drill 2 that may be electrically or hydraulically driven, displaces the drill 1 into the ground 4 while rotating the drill 1. Thus, a slit formed opening 6 is formed in the ground 4. The drill 1 is then removed from the slit formed opening 6.

A composite pole 8 that has been moved into the slit formed opening 6 is shown in FIG. 2. Additional fixing of the composite pole 8 to the ground 4 may be achieved by inserting grouting, fixing compound or other material (not shown) in between the composite pole 8 and the ground 4.

In an embodiment of the invention, shown in FIG. 3, a sleeve formed fastening element 10 is positioned in the slit formed opening 6. Additional fixing of the fixing element 10 to the ground 4 may be carried out as described for the composite pole 8. A composite pole 8 that is conical inside is placed about the fastening element 10 that has a conical upper portion 18, and moved against the fastening element until abutment is established.

In some cases, as when the ground 4 mainly constitutes suitable soil, the fixing element 10 may be forced into the ground 4 by hammering.

In a further alternative embodiment as shown in FIG. 4, the fastening element 10 is by its lower end portion 12 equipped with several drill elements 14. The section IV-IV in FIG. 5 shows a possible distribution of the drill elements 14 about the centre axis 16 of the fastening element 10. The drill elements may be made from material from the fastening element 10 or constitute other materials that is fixed to the fastening element 10.

A typical drill element 14 is shown in FIG. 6 where the drill element 14 that constitutes hard metal, is braced to the in use lover end portion lower end portion 12 of the fixing element 10.

The fixing element 10 shown in FIG. 4 is shown in two parts where in use an upper portion 18 that is fixed to the composite pole 8 is fixed to the in use lower portion 22 of the fixing element 10 by a flange connection 20. The lower portion 22 is here drilled into the ground 4.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb “comprise” and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. 

1. A fastening element for fastening a hollow composite pole for overhead power lines to the ground at a location where a slit-formed opening is present in the ground, the fastening element comprising a lower end portion that is configured for being positioned in the slit-formed opening, wherein the fastening element has a conical upper portion, wherein, in operational use of the fastening element, a conical portion of the composite pole is configured for moving over the conical upper portion of the fastening element until abutment with the fastening element is established.
 2. The fastening element according to claim 1, wherein the lower end portion of the fastening element is circular for allowing the fastening element to be placed in the slit formed opening being circular.
 3. The fastening element according to claim 1, wherein the fastening element at its lower end portion is equipped with drill elements.
 4. The fastening element according to claim 3, wherein the drill elements comprise metal.
 5. The fastening element according to claim 3, wherein the drill elements comprise ceramic material.
 6. A method for fastening a hollow composite pole for overhead power lines to the ground, the method comprising: making a slit-formed opening in the ground; inserting the fastening element into the slit-formed opening, and moving the composite pole that is conical, over the fastening element until abutment is established.
 7. The method according to claim 6, wherein the method comprises fixing the fastening element to the ground.
 8. The method according to claim 6, wherein the method comprises making the slit-formed opening by drilling into the ground.
 9. The method according to claim 6, wherein the method comprises making the slit-formed opening by hammering the fastening element into the ground.
 10. The method according to claim 6, wherein the method comprises providing the fastening element and drilling the fastening element into the ground.
 11. The fastening element according to claim 2, wherein the fastening element at its lower end portion is equipped with drill elements.
 12. The method according to claim 7, wherein the method comprises making the slit-formed opening by drilling into the ground.
 13. The method according to claim 7, wherein the method comprises making the slit-formed opening by hammering the fastening element into the ground.
 14. The method according to claim 7, wherein the method comprises providing the fastening element and drilling the fastening element into the ground.
 15. The method according to claim 8, wherein the method comprises providing the fastening element and drilling the fastening element into the ground. 